Direct Measurement of Particle Inertial Migration in Rectangular Microchannels

Abstract

Particles traveling at high velocities through microfluidic channels migrate from their starting streamlines due to inertial lift forces. Theories predict different scaling laws for these forces and there is little experimental evidence by which to validate theory. Here we experimentally measure the three dimensional positions and migration velocities of particles. Our experimental method relies on a combination of sub-pixel accurate particle tracking and velocimetric reconstruction of the depth dimension to track thousands of individual particles in three dimensions. We show that there is no simple scaling of inertial forces upon particle size, but that migration velocities agree well with numerical simulations and with a two-term asymptotic theory that contains no unmeasured parameters.

11 pages, 7 figures

References in corpus (1)

• Inertial migration of a rigid sphere in three-dimensional Poiseuille flow

Cited by in corpus (7)

• Inertial focusing of finite-size particles in microchannels
• Pairwise interactions in inertially-driven one-dimensional microfluidic crystals
• Bifurcations and dynamics in inertial focusing of particles in curved rectangular ducts
• Dynamics of small particle inertial migration in curved square ducts
• Instability of particle inertial migration in shear flow
• Inertial Focusing of Spherical Particles: The Effects of Rotational Motion
• Fast Asymptotic-Numerical Method For Coarse Mesh Particle Simulation In Channels Of Arbitrary Cross Section